This invention relates generally to seat back adjusters and specifically to a seat back adjuster to lock a seat back with respect to a seat cushion in an infinite number of reclined positions while permitting the seat back to be freely tilted.
Seat back adjusters in the prior art include several general types. One type includes a toothed member and one or more pawl elements engageable with the toothed member to lock the seat back in a plurality of positions. Typical of this type of seat adjuster is that shown in U.S. Pat. No. 4,143,905 to Hensel et al. Another type of adjuster includes a shaft receivable through a plurality of annular discs contained within a cylinder. In the locked position, the discs are tilted with respect to the cylinder. A release mechanism moves the discs to a perpendicular position to allow the seat back to be adjusted to a new position. Such an adjuster is shown in U.S. Pat. No. 3,366,416 to Tabor. Another type of seat adjuster uses a power operated screw jack mechanism.
All seat back adjusters must accommodate the arcuate rotating movement of the seat back with respect to the seat cushion frame. It is desirable that the adjusting mechanism itself be relatively simple and easily operable. A slide lock mechanism fulfills these objectives and has the additional features of providing a positive stop and being movable along a linear path.